Magazine floor plate

ABSTRACT

Magazine floor plates have a tubular body defining an elongated passage and having a lower end and an upper end, a floor plate element connected to the lower end, a follower movable within the elongated passage, a spring within the passage having a first end contacting the floor plate element, and having an opposed second end contacting and biasing the follower toward the upper end of the body. Downward force exerted by the spring on the floor plate element retains the floor plate element in an installed position relative to the lower end of the body. The floor plate element may have a width narrower than the elongated passage. The floor plate element may be connected to the lower end of the body by rails on the lower end of the body. The floor plate element may have an upward protrusion.

CROSS-REFERENCE TO RELATED APPLICATION

This is a Continuation of U.S. patent application Ser. No. 14/331,373,entitled “MAGAZINE FLOOR PLATE,” filed Jul. 15, 2014, which claims thebenefit of U.S. Provisional Patent Application No. 61/972,175 filed onMar. 28, 2014, entitled “TILT AND SLIDE MAGAZINE FLOOR PLATE.”

FIELD OF THE INVENTION

The present invention relates to firearms, and more particularly to amagazine floor plate for a box magazine.

BACKGROUND OF THE INVENTION

A magazine is an ammunition storage and feeding device within, orattached to, a repeating firearm. The magazine functions by moving thecartridges stored in the magazine into a position where they may bechambered by the action of the firearm. Most magazines designed for usewith a reciprocating bolt firearm utilize a set of feed lips which stopsthe vertical motion of the cartridges out of the magazine but allows onecartridge at a time to be pushed forward (stripped) out of the feed lipsby the firearm's bolt into the chamber.

Some form of spring and follower combination is almost always used tofeed cartridges to the lips, which can be located either in the magazine(most removable box magazines) or built into the firearm (fixed boxmagazines). As the firearm cycles, cartridges are moved to the top ofthe magazine by a follower driven by spring compression to a feedposition. In most firearms, the magazine follower engages a slide-stopto hold the slide back and keep the firearm out of battery when themagazine is empty and all rounds have been fired. Box magazines may beintegral to the firearm or removable.

A detachable box magazine is a self-contained mechanism capable of beingloaded or unloaded while detached from the host firearm. They areinserted into a magazine well in the firearm receiver usually below theaction, but occasionally positioned to the side or on top. When themagazine is empty, it can be detached from the firearm and replaced byanother full magazine. This significantly speeds the process ofreloading, allowing the operator quick access to ammunition.

Conventional pistol box magazines, such as the prior art 45 ACP magazine100 shown in FIG. 1, have a spring plate 116 with a downwardlyprotruding pin 120 that protrudes into a hole 122 in the floor plate 118to prevent removal of the floor plate. In order to remove the floorplate from the magazine body 112, a punch (not shown) is used to pressupwards on the button to disengage the spring plate from the floorplate. The magazine floor plate can then be slid forward toward thefront of the magazine and disengaged from the rails 124 on the bottom126 of the magazine. This process has the disadvantage of requiring atool in order to remove the floor plate. There is also a risk offorcible ejection of the spring plate by the compressed magazine spring114 once the floor plate is disengaged from the magazine. Conventional45 ACP magazines are also limited to seven rounds because the springplate and follower occupy a portion of the interior volume of themagazine.

Conventional rifle box magazines, such as the prior art AR-15 magazine200 shown in FIGS. 2A & 2B, has a floor plate 214 with an upwardprotrusion 218 near the front 216. The upward protrusion limits forwardmovement of the floor plate with respect to the magazine body 212. Thefloor plate is the same width as the magazine body. In order to removethe floor plate, a screwdriver 222 is inserted into the gap 224 betweenthe front edge 226 of the floor plate and the bottom edge 228 of themagazine 212. The floor plate is thin and flexible enough that the frontedge of the floor plate is pushed down to flex the floor plate so theupward protrusion can clear the front edge of the magazine body as thefloor plate is pried forward. This is enabled by the bent tabs thatsupport the plate from below being spaced away from the front face ofthe magazine, providing an elongated flexible cantilever that givesignificant flexing to allow the protrusion to clear the front edge. Thefloor plate can then be slid forward to disengage the floor plate fromthe tabs 220 on the bottom of the magazine. Also, the magazine body isdirectly above the plate about the entire periphery, so that it cannotbe pressed upward into the opening, even in the absence of springpressure, and must be flexed to clear the protrusion.

It is often desirable to increase the carrying capacity of a magazine.This is sometimes achieved by adding an extension to the lower end ofthe magazine, but this is often considered undesirable. Existingattempts to add capacity may exploit marginal available space whilekeeping convention floor plate dimensions, but this can havedisadvantages. For instance, eight-round magazines are offered forconventional Model 1911 pistol single-stack magazines without anextension, but these pack the rounds in so tightly that they do not letthe rounds depress. As a result, a loaded magazine may be installed onlywhen the pistol slide is retracted, because loading a full magazine whenthe slide is closed requires the stripper on the slide to be able todepress the rounds slightly. Consequently, such magazines are unable tocarry eight rounds plus one in the chamber of the associated firearm.

Therefore, a need exists for a new and improved magazine floor platethat can be removed from a magazine without tools, eliminates the needfor a spring plate, and enables a magazine to carry eight rounds with anadditional round in the associated firearm's chamber. In this regard,the various embodiments of the present invention substantially fulfillat least some of these needs. In this respect, the magazine floor plateaccording to the present invention substantially departs from theconventional concepts and designs of the prior art, and in doing soprovides an apparatus primarily developed for the purpose of providing amagazine floor plate that can be removed from a magazine without tools,eliminates the need for a spring plate, and enables a magazine to carryeight rounds with an additional round in the associated firearm'schamber.

SUMMARY OF THE INVENTION

The present invention provides an improved magazine floor plate, andovercomes the above-mentioned disadvantages and drawbacks of the priorart. As such, the general purpose of the present invention, which willbe described subsequently in greater detail, is to provide an improvedmagazine floor plate that has all the advantages of the prior artmentioned above.

To attain this, the preferred embodiment of the present inventionessentially comprises a tubular body defining an elongated passage andhaving a lower end and an upper end, a floor plate element connected tothe lower end, a follower movable within the elongated passage, a springwithin the passage having a first end contacting the floor plateelement, and having an opposed second end contacting and biasing thefollower toward the upper end of the body. Downward force exerted by thespring on the floor plate element retains the floor plate element in aninstalled position relative to the lower end of the body. The floorplate element may have a width narrower than the elongated passage. Thefloor plate element may be connected to the lower end of the body byrails on the lower end of the body. The floor plate element may have anupward protrusion. There are, of course, additional features of theinvention that will be described hereinafter and which will form thesubject matter of the claims attached.

There has thus been outlined, rather broadly, the more importantfeatures of the invention in order that the detailed description thereofthat follows may be better understood and in order that the presentcontribution to the art may be better appreciated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bottom perspective fragmentary exploded view of a prior art45 ACP magazine.

FIG. 2A is a top perspective fragmentary view of a prior art AR-15magazine with the floor plate partially removed.

FIG. 2B is a bottom perspective fragmentary view of the prior art AR-15magazine of FIG. 2A.

FIG. 3A is a top view of the current embodiment of the magazine floorplate constructed in accordance with the principles of the presentinvention.

FIG. 3B is a bottom view of the magazine floor plate of FIG. 3A.

FIG. 4A is a left side sectional view of the magazine floor plate ofFIGS. 3A & B installed on a prior art 45 ACP magazine.

FIG. 4B is an exploded view of FIG. 4A.

FIG. 5A is an enlarged left side sectional view of the magazine floorplate of FIGS. 3A& B installed on a prior art 45 ACP magazine.

FIG. 5B is a bottom view of FIG. 5A.

FIG. 6A is an enlarged left side sectional view of the magazine floorplate of FIGS. 3A& B installed on a prior art 45 ACP magazine showingthe first step of the floor plate removal process.

FIG. 6B is a bottom view of FIG. 6A.

FIG. 7 is an enlarged left side sectional view of the magazine floorplate of FIGS. 3A& B installed on a prior art 45 ACP magazine showingthe second step of the floor plate removal process.

FIG. 8 is an enlarged left side sectional view of the magazine floorplate of FIGS. 3A& B installed on a prior art 45 ACP magazine showingthe third step of the floor plate removal process.

The same reference numerals refer to the same parts throughout thevarious figures.

DESCRIPTION OF THE CURRENT EMBODIMENT

An embodiment of the magazine floor plate of the present invention isshown and generally designated by the reference numeral 10.

FIGS. 3A & 3B illustrate the improved magazine floor plate 10 of thepresent invention. More particularly, the magazine floor plate 10 is asubstantially planar body 12 having a top 14, bottom 16, front 18, rear20, left side 22, and right side 24. An upwardly protruding latch tab 30is located near the radiused front of the floor plate. The latch tab isoriented so the front 32 is a sharp step relative to the top of thebody, and the top 68 of the latch tab forms a gentle rearward-facingslope. The left side defines a left groove 26, and the right sidedefines a right groove 28. The left and right grooves begin rearward ofthe latch tab and extend to the rear of the body. In the currentembodiment, the latch tab is lanced in the body (the lance tool cutsthrough the body, but does not remove the material to leave a throughhole). The left and right grooves are coined in the bottom of the bodyin the current embodiment. In the current embodiment, the magazine floorplate is rigid, and preferably made of metal.

FIGS. 4A & 4B illustrate the improved magazine floor plate 10 of thepresent invention. More particularly, the magazine floor plate 10 isshown installed on a prior art 45 ACP magazine body 48. The magazinebody is depicted in a fully loaded condition with the body containingeight cartridges 46. In the current embodiment, the cartridges are 45ACP cartridges. The cartridges are held at an upwardly sloped angle bythe top 44 of a follower 40 with their rears lower than their fronts.Spring force exerted against the bottom 42 of the follower 40 by the top38 of a coil spring 34 urges the follower and cartridges 46 upwardswithin the magazine body.

The body 48 is generally tubular with an interior surface 66, and has afront 58, rear 60, left side 62, right side 64, top 52, and bottom 50.The left and right sides of the bottom of the body define elongated leftand right rails 54, 56.

The bottom 50 of the magazine body 48 is open to receive the follower 40and the coil spring 34. The magazine floor plate 10 closes the bottom 50of the magazine body 48. The body 12 of the magazine floor plate 10 hasa width so the body can be closely received within the bottom 50 of themagazine body 48. The left and right rails 54, 56 receive the left andright grooves 26, 28 on the body 12 of the magazine floor plate 10. Thelocation of the left and right grooves permits the magazine floor plateto slide into the left and right rails only from the front and limitsthe rearward movement of the magazine floor plate. The left and rightrails also limit side to side and downward movement of the magazinefloor plate. Forward movement of the magazine floor plate is limited bythe radiused step on the front 32 of the latch tab 30 on the body 12,while the rearward-facing sloped surface 68 facilitates rearwardmovement of the magazine floor plate during installation. The front 18of the body is entirely below the radiused front 58 of the magazinebody, and the rear 20 of the body is entirely below the rear 60 of themagazine body in the installed position, which prevents upward movementof the magazine floor plate.

Elimination of the prior art spring plate 116, along with a uniquefollower design, increases the capacity of the prior art 45 ACP magazinebody 48 from seven cartridges 46 to eight without requiring anymodifications to the magazine body. Furthermore, the additional spaceprovided by removal of the prior art spring plate enables the cartridgesto depress when the slide of an associated firearm is closed. Thisenables the otherwise unmodified firearm to carry eight rounds plus onein the chamber instead of either seven rounds in a conventional magazineplus one in the chamber or eight rounds in a modified magazine with nonein the chamber. Omitting the prior art spring plate also eliminates theneed for a through hole in the body 12.

FIGS. 5A & 5B illustrate the improved magazine floor plate 10 of thepresent invention. More particularly, the magazine floor plate is showninstalled on a prior art 45 ACP magazine body 48. In the installedposition, the rear 20 of the body 12 is flush with the rear 60 of themagazine body. Spring force exerted against the top 14 of the body 12 bythe bottom 36 of the spring 34 creates sufficient frictional engagementwith the left and right rails to maintain the rear justified position ofthe magazine floor plate under normal circumstances.

FIGS. 6A & 6B illustrate the improved magazine floor plate 10 of thepresent invention. More particularly, the first step of the magazinefloor plate removal process is depicted. After all of the cartridges 46have been removed from the magazine body 48, the arrow denotes how thebody 12 is pushed gently towards the radiused front 58 of the magazinebody until the step on the front 32 of the latch tab 30 is flush withthe interior surface 66 of the front of the magazine body. In thisposition, the rear 20 of the body is clear of the rear 60 of themagazine body.

FIG. 7 illustrates the improved magazine floor plate 10 of the presentinvention. More particularly, the second step of the magazine floorplate removal process is depicted. The arrow denotes how the bottom 16rear 20 of the body 12 is gently pushed upward into the open bottom 50of the magazine body 48. As the bottom rear of the body is pushed upwardinto the open bottom of the magazine body, the front 18 of the bodytilts downward about the front edges 70, 72 of the left and right rails54, 56. The bottom rear of the body continues to be pushed upward intothe open bottom of the magazine body until the step on the front 32 ofthe latch tab clears the front 58 of the magazine body and no longercontacts the interior surface 66.

FIG. 8 illustrates the improved magazine floor plate 10 of the presentinvention. More particularly, the third step of the magazine floor plateremoval process is depicted. The arrow denotes how the front 18 of thebody 12 is grasped and pulled gently forward to withdraw the rear 20 ofthe body from the open bottom 50 of the magazine body 48 and pull thebody free of the left and right rails 54, 56. The removal process isreversed to install the magazine floor plate.

In the context of the specification, the terms “rear” and “rearward,”and “front” and “forward” have the following definitions: “rear” or“rearward” means in the direction away from the muzzle of the firearmwhile “front” or “forward” means it is in the direction towards themuzzle of the firearm.

While a current embodiment of a magazine floor plate has been describedin detail, it should be apparent that modifications and variationsthereto are possible, all of which fall within the true spirit and scopeof the invention. With respect to the above description then, it is tobe realized that the optimum dimensional relationships for the parts ofthe invention, to include variations in size, materials, shape, form,function and manner of operation, assembly and use, are deemed readilyapparent and obvious to one skilled in the art, and all equivalentrelationships to those illustrated in the drawings and described in thespecification are intended to be encompassed by the present invention.For example, the magazine floor plate of the current invention issuitable for use with firearm magazines having calibers other than the45 ACP caliber described.

Therefore, the foregoing is considered as illustrative only of theprinciples of the invention. Further, since numerous modifications andchanges will readily occur to those skilled in the art, it is notdesired to limit the invention to the exact construction and operationshown and described, and accordingly, all suitable modifications andequivalents may be resorted to, falling within the scope of theinvention.

1. A magazine for a firearm for receiving an elongated cartridge havinga cartridge width and greater cartridge length, the magazine comprising:a tubular body having opposed major sidewalls defining an elongatedpassage and having a lower end and an upper end; the passage having across sectional profile having a width between the sidewalls adapted toclosely receive a cartridge width and a length adapted to closelyreceive a cartridge length; a floor plate element connected to the lowerend; wherein the floor plate element has a width narrower than theelongated passage; a follower movable within the elongated passage; aspring within the passage having a first end contacting the floor plateelement, and having an opposed second end contacting and biasing thefollower toward the upper end of the body; and wherein downward forceexerted by the spring on the floor plate element retains the floor plateelement in an installed position relative to the lower end of the body.2. The magazine of claim 1 wherein the floor plate element is rigid anddoes not bend while the floor plate element is being connected to andremoved from the lower end of the body.
 3. The magazine of claim 1wherein the floor plate element is connected to the lower end of thebody by rails on the lower end of the body.
 4. The magazine of claim 1wherein the floor plate element has an upward protrusion.
 5. Themagazine of claim 4 wherein the body has a radiused interior surface andwherein the upward protrusion has a corresponding radiused surface. 6.The magazine of claim 4 wherein the upward protrusion has arearward-facing sloped surface.
 7. The magazine of claim 4 wherein theupward protrusion is lanced in the floor plate element.
 8. The magazineof claim 1 wherein the elongated passage has a capacity of eightammunition cartridges when loaded.
 9. The magazine of claim 8 whereinthe follower and eight ammunition cartridges received within theelongated passage can be depressed sufficiently to install the loadedmagazine in a firearm with a closed slide.
 10. The magazine of claim 8wherein the ammunition cartridges are 45 ACP cartridges.
 11. Themagazine of claim 1 wherein a rear side of the floor plate element isflush with a rear side of the lower end of the body when the floor plateelement is in the installed position.
 12. The magazine of claim 1wherein at least a portion of the floor plate element may be elevatedinto the elongated passage.